Manufacturing Grooved Smoking Rods

ABSTRACT

A machine for making grooved smoking article rods has an axially rotatable drum ( 5 ) with a generally cylindrical outer surface ( 8 ). A pressing member ( 10 ) has a pressing surface ( 11 ) that includes grooves ( 12 ) facing the outer surface of the drum. The pressing member is heated by a heater ( 13 ). Filter rod segments ( 1 ) are fed from an inlet supply ( 9 ) between the pressing surface ( 11 ) and the drum ( 5 ) to be rotated and pressed against the grooves ( 12 ) so that a pattern of grooves ( 15 ) is formed in the outer surface of the filter segment.

FIELD

This specification concerns the manufacture of a grooved smoking article rod such as a grooved filter for a cigarette.

BACKGROUND

Hitherto, machines have been used to form longitudinal peripheral grooves in filter segments used in cigarettes. One example is described in U.S. Pat. No. 4,492,238 in which a cylindrical rod is formed with longitudinally extending grooves arranged around the rod's circumference, formed by heated elements disposed around the periphery of the drum over which the filter rod is arranged to rotate.

SUMMARY

Described hereinafter is an embodiment of a machine for making grooved smoking article rods, comprising an axially rotatable drum having a generally cylindrical outer surface, a pressing member spaced from and extending around a portion of the outer surface of the drum, the pressing member having a pressing surface that includes grooves facing the outer surface of the drum, a heater configured to heat the pressing surface, and an inlet feed to supply smoking article rods between the outer surface of the drum and the pressing surface when heated by the heater so as to be rotated by the rotation of the drum over the grooves and impress a pattern of grooves into the rod.

The pressing member may be configured to be retro-fitted to the rolling drum of apparatus for wrapping tipping paper around a smoking article such as cigarette, which has a rolling plate with a surface facing the drum for rolling tipping paper around the circumference of a filter segment and a coaxial rod of smokeable material. The retro-fittable pressing member may have a pressing surface that includes grooves to face the outer surface of the drum, a heater to heat the pressing surface, and a pressing member being so configured that smoking article rods passing between the outer surface of the drum and the pressing surface when heated by the heater are rotated by the rotation of the drum over the grooves to press the pattern of grooves into the rod.

The pressing member may be configured to be retro-fitted in place of the rolling plate, spaced from and extending around the portion of the outer surface of the drum.

Also described is a method a method of making grooved smoking article rods, comprising feeding smoking article rods between a generally cylindrical outer surface of an axially rotating drum and a heated pressing member spaced from and extending around a portion of the outer surface of the drum, the pressing member having a pressing surface that includes grooves facing the outer surface of the drum such that the rods are rotated by the rotation of the drum over the grooves and become impressed with a pattern of grooves corresponding to the grooves in the pressing surface.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more fully understood, an embodiment thereof will now be described by way of illustrative example, with reference to the accompanying drawings in which:

FIG. 1 is a schematic side view of a machine for making grooved smoking article rods that comprise filter rods in this example;

FIG. 2 is a schematic illustration of a filter rod prior to having grooves formed in its periphery by the machine of FIG. 1;

FIG. 3 illustrates the filter rod of FIG. 2 after having been formed with grooves by the machine of FIG. 1;

FIG. 4 is a perspective schematic illustration of a cigarette that includes a grooved filter made by the machine of FIG. 1;

FIG. 5 is a longitudinal sectional view of another form of cigarette that utilises a grooved filter made by the machine of FIG. 1; and

FIG. 6 is a partially exploded perspective view of the cigarette illustrated in FIG. 5.

DETAILED DESCRIPTION

Referring to FIG. 2, a filter rod 1 comprises filter material, for example cellulose acetate tow 2 wrapped in a plug wrap 3. The tobacco rod may be made in essentially continuous lengths which are cut into segments. In some cigarette manufacturing processes, the cut segments correspond to a length of two cigarettes manufactured end to end which are subsequently cut apart from one another. However, for the purposes of illustration, FIG. 2 illustrates a segment suitable for an individual cigarette. As shown in FIG. 2, the segment is generally cylindrical about a longitudinal axis of symmetry X-X′. The cylindrical surface 4 is initially smooth, i.e. ungrooved in this example.

Referring to FIG. 1, successive filter rod segments 1 are caused to roll between a drum 5 that rotates about axis 6 in a direction of arrow Y. The drum has a series of axially extending, circumferentially spaced grooves 7 in its exterior cylindrical surface 8 that act as receptacles that receive successive ones of the filter segments 1 fed from an inlet feed hopper 9.

A generally arcuately extending pressing member 10 has a curved pressing surface 11 which is generally coaxial with axis 6. The pressing surface 11 is formed with a pattern of uniformly spaced grooves 12 that extend in a direction parallel to the rotational axis 6 of the drum. The pressing member includes an electrical heater 13 driven from an electrical power supply (not shown). In use, the filter segments 1 are fed successively from the inlet hopper 9 into an arcuate gap 14 between the cylindrical surface 8 of the drum 5 and the pressing member 10. Successive ones of the filter segments 1 are received in individual grooves 7 in the drum 8. On rotation of the drum 5 in a direction of arrow Y, the segments 1 are entrained into the gap 14 and are rotated over the grooves 12 in the pressing surface 11, which is heated by the heater 13 so as to form a regular pattern of grooves 15 that as shown in FIG. 3, extend parallel to the axis X-X′ around the cylindrical surface of the filter segment so as to form a grooved filter segment 1′.

The filter segments 1 thus travel in a direction of arrow A in the peripheral gap 14 to an outlet area 16 from which the resulting grooved filter segments 1′ fall in a direction of arrow B into a receptacle (not shown) for subsequent assembly into cigarettes.

A kick bar 17 is provided on the pressing surface 11 in order to encourage each grooved filter segment 1′ to release itself from the receptacle 7 in which it was guided during passage along the annular gap 14 during the groove forming process. More than one such kick bar 17 may be provided along the pressing surface 11 in order to ensure proper rotation of the filter segments as they move along the pattern of grooves 12.

The grooves may have a depth of between 0.2 to 2.0 MM, more particularly from 0.2 to 1.0 mm, from 0.5 to 1.0 mm, from 1.0 to 2.0 MM or from 1.5 to 2.0 MM, and may be for example spaced with a periodicity of 0.5-2 mm. It will be appreciated that any suitable grooving pattern may be formed by appropriately configuring the pattern of grooves 12 in the pressing surface 11. The radial spacing D between the pressing surface 11 and the axial surface 8 of the drum 5 is suitably selected in order to ensure that the filter segment 1 is subject to compression whilst rotated and moved in the direction of arrow A and in this way, the pattern of grooves 12 is pressed into the cylindrical surface of the filter rod segment 1.

The electrical heater 13 heats the pressing surface 11 to warm the plug wrap 3 so as to form a stable groove pattern 15 in the cylindrical surface 4 of the filter segment 1. Conveniently, the pressing surface is heated to a temperature of between 150-250° C. for this purpose.

Typically, the grooves are spaced so as to form 20-40 grooves 15 around the circumferential surface 4 of the filter segment 1. However, a smaller or greater number of grooves of a selectable, appropriate depth can be formed as required by suitably configuring the pattern of grooves 12.

The pressing member 10 is mounted on a shaft for rotation about axis W and can be locked in position by means of locking mechanism (not shown). The locking mechanism allows movement of the pressing member radially in a direction Z-Z′ in order to allow adjustment of the pressure imparted to the filter segments 1 as they move along the gap 14 during the groove forming process. Also, the pressing member can be adjusted in a direction of arrow D transversely of axis W in order to configure the pressing member 10 to have a uniform radial distance D along the length of the gap 14 or to slightly taper the gap 14 along its length.

Typically in cigarette manufacture, filter segments are attached to a rod of smokeable material by means of tipping paper which is rolled around the circumference of the rod of smokeable material and the filter. Conventionally, a rolling machine is utilised which has a drum generally similar to the drum 5 shown in FIG. 1. A curved rolling plate with a surface facing the drum is used to roll the tipping paper around the circumference of filter segments and coaxial rods smokeable material in order to attach each of the segment to a respective rod of smokeable material. An example of a rolling machine is the Hauni Max 5 manufactured by Hauni Maschinenbau AG. In order to provide the apparatus shown in FIG. 1, the rolling plate of a conventional rolling drum machine may be removed and replaced by the pressing member 10 shown in FIG. 1 as a retro-fit modification of the rolling machine.

FIG. 4 illustrates a first example of cigarette that utilises a grooved filter segment produced by the machine at FIG. 1. The cigarette comprises a rod 18 of smokeable material such as tobacco in a paper wrapper 19 to which a filter segment 1′ is attached by means of tipping paper 20 that surrounds one end of the tobacco rod and also the cylindrical surface of the filter segment 1′ so as to bridge the groove 15 and provide circumferentially spaced, axially extending passageways from the proximal or mouth end of the filter 21 to its distal end 22. Ventilation holes 23 are formed in the tipping paper at the distal end 22 of the filter 1′ for example by laser cutting in order to allow ventilation air to enter into the grooves 15 and be drawn into the user's mouth along with smoke created by combusting the rod 19.

Another example of a cigarette that uses a grooved filter segment 1′ is illustrated schematically in FIGS. 5 and 6. In this example, the grooves 15 in the filter segment 1′ are used in combination with an element 24 as an indexing mechanism. The smoking article includes a rod 18 of smokeable material as previously described, circumscribed by a paper wrapper 19. Tipping paper 20 attaches a first filter segment which comprises a filter segment 1′ formed with grooves 15 along at least a major part of its cylindrical surface 4. A second filter segment 25 is arranged in axial abutment with the first segment 1′ in respect to the axis X-X′. The second segment has a generally smooth cylindrical outer surface 4 i.e. no grooves have been formed in it. An outer wrapper 26 surrounds the filter segments. The wrapper 26 is glued to the second segment 25 and also, the element 24 is glued onto the interior surface of the wrapper 26 in alignment with the grooves 15. As shown in FIG. 5, when assembled the element 24 engages with the grooves 15 to provide an indexing mechanism which produces an audible click upon rotation of the outer wrapper 26. The filter may be provided with an adjustable ventilation mechanism (not shown) that can be adjusted by rotation of the first filter element relative to the second filter element about the axis X-X′. The indexing mechanism 15, 24 allows controlled rotation of the filter elements relative to one another and also provides the user with an audible indication of the rotation. It will be appreciated that in practice, structural elements will be provided in order to prevent the wrapper 26 from sliding axially away from the cigarette but this has been omitted from FIGS. 5 and 6 for the purpose of simplicity of explanation.

Many modifications and variations with described examples will be evident for those skilled in the art. For example, the groove 15 may not be continuous as shown in FIG. 3 and may be made up of more complex segments which need not necessarily be axially aligned.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced and provide for superior machines and methods for making grooved smoking article rods. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilized and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future. 

1. A machine for making grooved smoking article rods, comprising: an axially rotatable drum having a generally cylindrical outer surface; a pressing member spaced from and extending around a portion of the outer surface of the drum, the pressing member having a pressing surface that includes grooves facing the outer surface of the drum; a heater configured to heat the pressing surface; and an inlet feed to supply smoking article rods between the outer surface of the drum and the pressing surface when heated by the heater so as to be rotated by the rotation of the drum over the grooves to impress a pattern of grooves into the rod.
 2. The machine according to claim 1 including a plurality of axially extending circumferentially spaced receptacles in the cylindrical surface of the drum to receive individual ones of the smoking article rods.
 3. The machine according to claim 1 including at least one kick bar on the pressing member to promote rotation of the smoking article rods along the pressing surface.
 4. The machine according to claim 1 wherein the grooves in the pressing member extend generally parallel to the axis of the drum.
 5. The machine according to claim 1 wherein the pressing surface extends generally coaxially around part of the outer surface of the drum.
 6. The machine according to claim 1 wherein the grooves have a depth of between 0.2 to 2.0 mm.
 7. The machine according to claim 1 wherein the grooves are of substantially the same depth and regularly spaced so as to form a regular grooved pattern around the circumference of the smoking article rods.
 8. The machine according to claim 1 wherein the heater is configured to heat the pressing surface to a temperature of between 150-250° C.
 9. A pressing member configured to be retro-fitted to the rolling drum of an apparatus that has a rolling plate with a surface facing the drum for rolling tipping paper around the circumference of a filter segment and a coaxial rod of smokeable material, the pressing member having a pressing surface that includes grooves to face the outer surface of the drum, a heater configured to heat the pressing surface, and the pressing member being so configured that smoking article rods passing between the outer surface of the drum and the pressing surface when heated by the heater are rotated by the rotation of the drum over the grooves to impress a pattern of grooves into the rod.
 10. The A pressing member according to claim 9 and being adapted to be fitted in place of the rolling plate spaced from and extending around a portion of the outer surface of the drum.
 11. A method of making grooved smoking article rods, comprising: feeding smoking article rods between a generally cylindrical outer surface of an axially rotating drum and a heated pressing member spaced from and extending around a portion of the outer surface of the drum, the pressing member having a pressing surface that includes grooves facing the outer surface of the drum such that the rods are rotated by the rotation of the drum over the grooves and become impressed with a pattern of grooves corresponding to the grooves in the pressing surface.
 12. The method according to claim 11 wherein the smoking article rods comprise filter rods, and including impressing the grooves longitudinally into the filter rods.
 13. The method according to claim 12 wherein the filter rods comprise cellulose acetate tow wrapped in a plugwrap, and including forming the grooves by impressing the plugwrap.
 14. The method according to claim 13 including attaching a tobacco rod to the filter rod or a segment thereof using said rotary drum.
 15. A method of making grooved smoking article rods, comprising: heating a pressing member spaced from and extending around a portion of an outer surface of an axially rotating drum; singularly feeding a plurality smoking article rods into spaced grooves on the outer surface of the rotating drum such that the smoking article rods are positioned between the cylindrical outer surface of the rotating drum and the pressing member; rotating the axially rotating drum to rotatably pass the smoking article rods against a grooved surface of the pressing member; impressing on the outer surface of each of the smoking article rods a pattern of grooves; wherein the pressing member has a pressing surface that includes the grooves facing the outer surface of the rotating drum such that the rods are rotated by the rotation of the drum over the grooves and become impressed with the pattern of grooves corresponding to the grooves in the pressing surface. 